Newhaven Display Forum

Newhaven Products => TFTs => Topic started by: mjhuslig on November 19, 2016, 01:31:27 PM

Title: NHD-2.4-240320CF-CTXI#-F spec on VDDIO
Post by: mjhuslig on November 19, 2016, 01:31:27 PM
I want to use the NHD-2.4-240320CF-CTXI#-F in a battery application.  The uP and VDDIO connected to the battery and VDD connected to a charge pump controlled by the uP.  When the unit is off, the uP turns off the charge pump and goes to sleep.  Can VDDIO be left powered while VDD is off?  What is the current draw on VDDIO if it were left powered?
Title: Re: NHD-2.4-240320CF-CTXI#-F spec on VDDIO
Post by: Saurabh_B on November 22, 2016, 12:18:14 PM
Hello,

We often recommend tying the VDDIO to the VDD pin.
The 3.3V is still within the safe operating voltage for the Controller IC.

According to the Datasheet (Page 131), the VDDIO needs to be powered down before the VDD.
Datasheet: http://www.newhavendisplay.com/app_notes/ST7789S.pdf

Because of these we have not tried to test power drain while VDD is not applied.